Security remained high this week at Los Angeles International Airport and train stations across the region in response to the terror attacks at the international airport and a subway station in Brussels that killed more than 30 people and injured more than a hundred.

“We take attacks on aviation very seriously,” Hernandez said, promising they will “make adjustments to security as necessary.”

U.S. Department of Homeland Security Secretary Jeh Johnson said that while there are no credible threats against any domestic targets, the Transportation Security Administration will be adding personnel at airports across the country.

“As a precautionary measure, TSA is deploying additional security to major city airports in the United States and at various rail and transit stations around the country,” Johnson said. “TSA is also working closely with state and local law enforcement, airport authorities and the aviation industry in order to augment that security.”

There were no impacts to flight operations at LAX Tuesday, although traffic was at one point reported to be heavy on the upper level of the airport loop, in part due to the large number of media trucks parked along the roadway.

Armed guards were noticeably increased at Union Station in downtown Los Angeles and at other Metro stations, including the Metro Blue Line’s Rosa Parks station in Willowbrook and the Seventh Street/Metro Center station at Seventh and Figueroa on Tuesday.

“Metro and the Los Angeles County Sheriff’s Department Transit Policing Division are aware of the terrorist strikes in Belgium and are monitoring the situation closely,” according to Metro. “While we maintain a high state of readiness at all times, we will be increasing security.”

There is no tangible threat to any transit system in Los Angeles, sheriff’s department Transit Services Bureau spokesman Ramon Montenegro told City News Service.

“Right now, we are monitoring the situation in Brussels and maintaining close contact and communications with our county Emer­gency Operations Center, Home­land Security and LA Metro,” Montenegro said.

“I’m certain that we will increase security in the aftermath of these attacks on all transit lines,” Montenegro said. “We also have special security teams that we will likely deploy later today.”

Montenegro said the security patrols include bomb-sniffing dogs that are regularly deployed along the Red Line subway route and other Metro lines.

“Our hearts go out to the people of Brussels and to the first responders,” he said. “We just pray that no one else gets hurt there.”

Metro officials asked the public to be aware of their surroundings at transportation centers and stressed the importance of calling attention to something or someone that may seem unusual.

“We are asking the public to be our eyes and ears on the system,” according to a Metro statement, “If you see something, say something.”

Los Angeles County Sheriff's Department officials said that in addition to the increased security at transportation hubs, the agency’s Special Operations Division resources “are on standby and are prepared to respond anywhere in the region should the need arise.”

“There is no credible information that attacks are likely here, but as always, we ask the public if they ‘See Something, Say Something,’” according to the department.

LAPD officers were deployed to a variety of high-profile sites that tend to be gathering points for large crowds — such as the Grove shopping center, synagogues, the Beverly Center and Hollywood & Highland.

Amtrak spokeswoman Verna Graham said the rail line also has added safety personnel.

“Amtrak police are working with state, local and federal law enforcement partners to gather and share intelligence,” Graham said. “Extra officers have been deployed. We have reminded Amtrak employees to look for and report any suspicious activity and unattended items and reissued guidance pertaining to facility inspections and active shooter incidents.”

Metrolink also enhanced its security and is coordinating with a variety of law enforcement agencies, Public Affairs Officer Scott Johnson said. The same goes at the Port of Los Angeles, where spokes­man Phillip Sanfield acknowledged “a proactive presence with L.A. Port Police at our containment terminals, cruise terminals and throughout the port complex.”